Evaporative condenser



Dec. 22, 1942. F. w. GILMAN EVAPORATIVE CONDENSER Filed June 28, 1940INVENTOA FRANKLIN vv. GIL MAN y W ,L/

Patented Dec. 22, 1942 EVAPOBATIVE CONDENSER.

Franklin W. Gilman, Philadelphia, Pa., assignor to C. F. Moores 00.,linc., Philadelphia, corporation of Delaware Application June 28, 1940,Serial No. 342,867

1 Claim.

This invention relates to an improvement in evaporative condensers orcoolers, and particularly in evaporative condensers for use in arefrigeration system.

As is well known, mechanical refrigeration systems using a vapor readilyliquefiable under pressure, as, for example, sulfur dioxide, ammonia,etc., comprise an evaporator, a compressor, and a condenser. In smallinstallations the condenser may be air cooled, but in refrigeratingsystems of any substantial capacity, the condenser is water cooled.

Since in many installations the cost of cooling water is a major factorin the operating cost of the refrigerating system, it is desirable touse a type of condenser which will consume a minimum amount of water,and it has accordingly been proposed to use for this purpose evaporativecondensers, i. e., a condenser in which the outer surface of thecondenser tubes is kept constantly wet by a film of water, over which acurrent of air may be passed to accelerate evaporation.

It is a purpose of this invention to provide a simp.e, compact andeficient evaporative condenser, particularly adapted for use inrefrigeration systems. The manner in which this and other purposes ofthis invention are attained will be apparent from the followingdescription of a preferred embodiment of this invention, read inconnection with the accompanying drawing, in which:

Figure l is a vertical section through a preferred type of condenser inaccordance with this invention; and

Figure 2 is a section on the line 2-2, in Fig. l.

A sheet metal tank I forms the base of the apparatus and serves as asupport for the other elements thereof. This tank is, in use, keptfilled with water to a predetermined level by means of a floatcontrolled valve 25 in the water supply line 25. A metal cover plate 3forms the top of tank I, and is welded or otherwise secured thereto. Acasing 2 is secured to the cover plate 3, which is cut away within thecasing 2, as shown in Fig. 1. The casing 2 is, in plan section, in theform of a scroll, and terminates in an upwardly opening elbow 24, whichserves as an air outlet from the apparatus. The top 2a of casing 2 isprovided with a central aperture 22). An electric motor 6 is supportedfrom plate 212 centrally above the aperture 2b on brackets 1.

Within the casing 2 the condenser tubing l1, through which the medium tobe cooled or condensed passes, is placed, preferably in one or cientturns to fill casing 2 from top to bottom. Two coils are shown in thedrawing, arranged in parallel with an inlet header 23 and an outletheader 24. However, any desired number of coils may be used, and thecoils may be in parallel or comprise a single continuous tube.Preferably where several coils are used, they will be wound alternatelyin opposite directions. While it is not necessary for satisfactoryoperation, the tubing I1 will preferably be provided with fins I8 so asto increase the effective surface thereof.

The tubing lI may conveniently be secured, as by soldering, to the plate2a and supported therefrom. A plate 5 having an aperture 511 concentricwith aperture 217 is secured to plate 3' and closes the bottom of casing2. Baffles l9 and Na close the space between the coils of tubing [1 andthe top 2a and bottom 5, respectively, of casing 2.

A centrifugal, multivane type fan 9 is mounted in casing 2 within andclosely adjacent the inner coil of tubing 11 on shaft 8, which isconnected at its upper end to the drive shaft of motor 6 and is securedat its lower end in the bearing 20 mounted in bracket 22 suspended fromplate 5. The bearing 20 has a rubber lining 2| and will operate underwater without other lubrication. Preferably, as shown in Fig. 1, the fan9 is of the double inlet type, with a hub plate H1 in the center, but asingle inlet type may be used if desired. Air for the top half of thefan is supplied through ring 4 secured to the top 2a of casing 2 aboutthe aperture 2b; and for the lower half, through aperture 21 in plate 3,beneath plate 3 above the water level and into the fan through theaperture 5a in plate 5.

Water for keeping the tubing l1 wet is supplied through a plurality oftubes, arranged to rotate with the fan wheel 9, the lower ends of whichare placed beneath the water level in tank 1 adjacent the axis ofrotation and the upper ends of which are located within the fan wheel 9and are spaced from the aXis of rotation. The tubes are to be arrangedabout the fan wheel in groups of two or more, so that they will be inrotative balance. In the drawing, which illustrates the most simplearrangement, two substantially straight tubes II and I2, respectively,are placed diametrically opposite one another within the fan wheel at anangle to the axis thereof. The tubes, which should be of exactly thesame length are placed with their upper endstouching, or nearlytouching, the blades of the fan 9, while the lower endsextend below thewater level in more close coils in the form of a helix of sufiitank Iand are bent, as shown, to provide openings facing in the direction ofrotation of the fan'and lying closely adjacent the axis thereof. Thetubes l I and I2 are secured in place by being passed through aperturesin the hub plate In and fastened, at their lower ends, as by soldering,to the shaft 8.

The tops of tubes II and I2 are closed, and tube ll, serving the upperportion of the structure, is provided with an aperture l3 in the outerside of the tube closely adjacent the top. Tube l2, serving the lowerportion of the structure, is provided with a similar aperture M in itsouter side at a level below the hub plate Ill, and also with a minuteair hole IS in aside of the tube closely adjacent thetop. This insuresthat both tubes will n11 with water for their entire lengths, and willso be in rotative balance when filled. Similarly where v.morethan twotubes are used, each tube not provided with a water discharge apertureat its top will have an air hole at the top in addition to a waterdischarge aperture at alower level.

In operation, rotation of the fanwheel 9 by motor 6 draws a stream ofair throughaperture 2'! and ring 4 into the casing Zand :forces it overthe coils of tubing 11, whence it is discharged through outlet 24. Atthe same time tubes H and [2 are rotated and water is drawn bycentrifugal force up through the tubes .from tank I, and discharged as aspray through the fan blades onto the coils of tubing H from aperturesl3 and I4 respectively. The coils of tubing I! act as a bafiie, and due:to this action and the turbulence of the air stream leaving the fan 9,the spray leaving tubes H and 12 is quickly broken up and wets theentire surface of tubing l1. Substantially no spray passes through thecoils of tubing, which as stated are closely spaced and preferably woundin opposite directions, to be carried out through the outlet 24. Excesswater falling from the condenser tubing l1 re- In an evaporativecondenser or cooler, spray- ,ingmeans. comprising a plurality of tubesarranged for rotation as a group about a vertical axis, the lower endsof said tubes being open, the upper ends of said tubes being closedexcept as otherwise specified herein and located at a greater radialdistancefrom the axis of rotation of the group of tubesx than the lowerends thereof, the walls of said tubes being provided with apertures,certain of said tubes having said apertures at different vertical levelsthan others of said tubes, .and a relatively minute aperture for theescape of'occluded air located at the extreme upper end of eachsaid tubethat is not provided with a wall aperture at substantially that. level,whereby all saidtubes may be filled for their entire length byliquid-drawn into them by centrifugal force on rotation of the group oftubes and so remain in rotative balance.

